This invention relates to a device which prevents corrosion, the formation of scale, and dislodges existing scale in a water system. Furthermore, the present invention relates to a water treatment device or "cell" for treatment of water or water-based solutions to prevent corrosion in water treatment equipment, such as, heat exchangers, cooling towers, municipal or household water systems. Even further, the present invention relates to the treatment of other chemical solutions to alter the break-down or reactions occurring therein.
In the treatment of water for use in cooling towers, heat exchangers and power generation, the water used in these systems generally comes from canals, rivers, lakes, wells and the like. Such water usually contains relatively high amounts of compounds which include the elements calcium, carbon, sulphur, magnesium, and silicon, as well as bicarbonates which stick or adhere to the walls of the tubes in the heat exchangers or the water cooling towers as well as the pipes or conduits in the equipment through which the water is being transported. Moreover, corrosion of this equipment is also prevalent. The build up of these minerals and their salts accumulate to form scale deposits; thereby, resulting in diminished heat transfer, an increase in the consumption of energy, and a decrease in the working life of the parts to which this mineral containing water is in contact. Furthermore, in the use of water from these streams, lakes, canals and the like without treatment, algae, slime, microorganisms, etc. multiply rapidly and produce masses of these organic living cells which also reduce the transfer of heat as they attack the surfaces of heat exchange tubes and the other parts of the water systems and form deposits thereon.
In most systems water treatment chemicals (water softeners) are added directly into the water supply prior to use to precipitate out many of these aforementioned metallic compounds including the salts, as well as the organic microorganisms that are free to develop. In the use of these chemicals to treat these water systems, the economics are generally quite high, chemicals are constantly being purchased and furthermore the precipitates which occur from the water treatment process also have to be frequently removed. One process for treating water including significant calcium and magnesium concentrations is described in U.S. Pat. No. 4,882,064. In this particular reference, water is contacted with a coagulant/absorbent which comprises a finely divided particulate mineral material, particularly magnetite, which reacts with the calcium and magnesium compounds in the water, the resulting reaction mix being subjected to a filtration or decantation process.
One way for the metal in the transfer system such as an iron pipeline to be protected is for the metal to be in contact with a more active electron donor. An example would be to coat the iron with another metal that will preferentially corrode, thereby saving the iron. Such protection is often referred to as providing a "sacrificial anode". Another method of protecting metal is to paint the metal with a non-conducting organic paint to keep the hydrogen ions and oxygen from touching the metal, thereby preventing the reduction reaction from occurring.
Moreover, there have been physical processes or methods for treating water to replace the chemical treatment of water and at least one such process is known and has limited success. This physical process includes the insertion of a sealed brass container which includes a number of elements therein, particularly zinc, magnesium, iron, silver, copper, potassium and magnesium, which has found limited success in the prevention of scale build-up in water systems.